OK, I looked at the photo I shot of the crane and it indeed has no dash, but I suspect it is some sort of error, as the model marking is "6291" which I suspect is the equivalent of "629-1". All my other S&W revolvers have an explicit dash.

In any case, from what y'all have written, it was not until 629-3 that the 629 got the Endurance Package and all before that ought to be limited to 240gr pills at the usual factory velocities.